1. Field of the Invention
The present invention relates to a method used in a wireless communication system, and more particularly, to an access control method in a wireless communication system to enable a wireless access point to dynamically grant access permission to a wireless client.
2. Description of the Prior Art
A wireless access point offers wireless connection services for a wireless device to connect to wired networks and or the other wireless devices, using WiFi, Bluetooth, or other standards. The wireless access point may apply security mechanisms, such as Wired Equivalent Privacy (WEP), Wi-Fi Protected Access (WPA) or WPA2, to protect the network from information leakage and unauthorized access. When these security mechanisms are enabled, the clients will need to obtain a pre-shared key (PSK) or certificate before being able to access the wireless network.
While WEP and WPA-PSK can provide protection to a certain level, they are still subject to the dictionary attacks or brute force attacks. Using cracking tools, like aircrack-ng, it is possible for one to crack a weak key in several minutes. A good practice for network administrators to block these kind of attacks is to use strong keys, for example, a 13-character-long truly random key, and change it every so often. However, changing keys for wireless network is troublesome for network administrators, for example, they will need to distribute the new keys to the users and the users need to re-entered the keys to the clients' wireless configuration UI (user interface). So many administrators tend not to change the keys very often, and even worse some may use same keys for different wireless networks. As a result, their wireless networks become prone to hackers' attacks and or unauthorized accesses.